Pipe rack for well drilling apparatus



Sept. 5, 1967 G. D. SHERMAN PIPE RACK FOR WELL DRILLING APPARATUS 2 Sheets-Sheet .1

Sept. 5, 1967 e. D. SHERMAN PIPE RACK FOR WELL DRILLING APPARATUS 2 Sheets-Sheet 2 Filed June 14, 1965 United States Patent Ofiice 3,339,747 Patented Sept. 5, 1967 3,339,747 PIPE RACK FOR WELL DRILLING APPARATUS George D. Sherman, Houma, La., assignor to Texaco Inc., New York, N.Y., a corporation of Delaware Filed June 14, 1965, Ser. No. 463,665 2 Claims. (Cl. Z1160) ABSTRACT or THE DISCLOSURE Apparatus for racking drill pipe in a floating platform comprising a pipe well suspended from the drilling platform, such pipe well having an inclined bottom and a pipe distributing member movable at right angles to the direction of inclination of the floor of the pipe well.

The present invention relates to a novel pipe rack construction for well drilling apparatus. More particularly it concerns well drilling apparatus for drilling oil wells in offshore areas, using floating or stationary drilling platforms, wherein a novel pipe rack is employed to lower the center of gravity and to improve the safety, efliciency and ease of handling the pipe required for drilling or casing an oil well.

In well drilling operations the drill pipe and tubing strings (pipe being used herein to designate both) are generally racked vertically on the derrick with their lower ends on the drilling platform. While this does not pose particular problems when drilling on land, it does create problems at sea where a floating platform may be pitching with the waves or where a normally stationary platform is being transported from one well to another as a floating barge. Under such conditions the upwardly extending pipe may raise the center of gravity so high as to cause violent rolling or even capsizing of a floating barge, and the stresses on the drilling mast may be severe enough to damage it.

In accordance with the present invention there is provided a novel pipe rack for offshore well drilling apparatus which overcomes the drawbacks of the prior art and makes it much easier and safer to handle pipe than heretofore. My improved pipe rack comprises an elongated hollow box having an open upper end which is secured to a drill platform near its surface and near the rotary turntable, and a lower end which is closed by a floor located well below the surface of the platform. The floor of the box is an inclined plane so that each length of pipe when lowered into the box strikes the floor and slides down to the lowest unoccupied position in the box. When pipes of equal lengths are to be racked, which is generally the case, this construction also develops a staggered arrangement of the pipe at the top of the rack so that it is relatively easy for a derrick man to attach the hoisting machinery to each pipe as needed, to pull it from the rack and insert it in the rotary table.

Additionally, I have provided a novel mechanism for assuring that the pipes are distributed evenly within the box, this comprising a pipe distributing device carried by the box near its lower end and movable in opposite directions transversely therein. This device has a planar top surface which is inclined at about 90 to the floor inclination so that as each length of pipe is lowered into the box it first strikes the top surface of the distributing device, then slides down and strikes the inclined floor of the box, whereupon it slides down the floor in a direction normal to its original slide into its proper position. Upon completion of each row the distributing device is moved away sufficiently so that the pipes can be introduced into the next row.

The invention will be described more in detail hereinafter with reference to the accompanying drawings wherein:

FIG. 1 is a schematic side elevational view of a drilling platform carrying a pipe rack in accordance with the invention;

FIG. 2 is an enlarged side elevational view, parts being shown in section, of the pipe rack as viewed from the line 22 in FIG. 1;

FIG. 3 is a vertical sectional view, parts being in elevation, of the pipe rack taken along the line 3--3 in FIG. 2;

FIG. 4 is an enlarged cross-sectional view, parts being shown in elevation, taken along the line 44 in FIG. 2; and

FIG. 5 is a bottom view of the pipe rack taken along the line 55 in FIG. 2.

Referring to FIG. 1 there is shown a drilling platform P which is supported by legs L on the sea bottom. Platform P is of the well-known barge type wherein the legs L can be vertically raised so that the platform floats on the water for transportation from one well to another. A conventional derrick mast D is positioned on the platform over a conventional rotary table T positioned above a surface casing C which extends to the Sea bottom, and through which the drilling operation is conducted.

At R is shown the novel pipe rack of the present invention, which is Secured near its upper end to the platform P at a position adjacent to the turntable T so that the conventional derrick (not shown) can be used for raising the pipe from the rack and inserting it into the turntable. Rack R extends down below the surface of the platform and into the water. It is evident that with this construction the platform is relieved of the clutter of pipes which otherwise would have to be stacked on the platform itself. Also, when the platform is floating, the center of gravity is kept low so as to prevent undue pitching of the barge during its transportation from one well to another. The derrick man, of course, can handle the pipes from the platform surface instead of having to work dangerously near the top of the derrick mast.

Referring to FIGS. 2 to 4, the pipe rack R is shown in detail as comprising an elongated rectangular box 11 which at its upper open end is welded or otherwise secured to a girder 13 of the drilling platform. The lower end of the box 11 is closed by a floor 15 in the form of an inclined plane having an upper edge 17 at one side of the box and a lower edge 19 at the opposite side whereby each length of pipe when lowered into the box strikes the floor 15 and slides down to the lowest unoccupied position thereof. The box 11 is shown as rectangular in cross-section and as made up of imperforate side walls. However, it is evident that the box could have other shapes, such as cylindrical, and that the walls could be perforate; or even that the box could be made up of spaced frame members rather than Side walls where the ocean currents are such that undue stresses upon the rack must be avoided.

With the simple structure described above, considerable maneuvering of the pipe by the derrick man may be necessary when stacking a large number of pipes in orderly rows. In order to make this operation more eflicient, rapid and easy for the derrick man, I have provided the pipe rack with a pipe distributing device 23 which is mounted on a bracket 25 welded or otherwise secured to opposite sides of the rack and projecting laterally therefrom. The distributing device 23 is mounted on the bracket 25 for movement in opposite directions through an aperture 26 and within the box, transversely thereof. The upper Surface of the device is planar and is inclined in a direction of about to the direction of inclination of the floor 15 with the lower edge 27 of the device being about level with the upper edge 17 of the floor. With this construction, when a pipe 29 is lowered into the rack it first strikes the inclined surface 23 and then slides down this surface in a first direction until it strikes the inclined floor 15, whereupon it slides down the floor 15 in a second direction normal to the first and into its final resting position. Upon completion of a row, as shown in FIG. 3, the distributing device 23 is moved away from the row (to the left in FIG. 2) a sufficient distance so that the next row of pipe can be racked in the same manner alongside the previous row.

Referring to FIGS. 2 and 5, for operating the distributing device 23 a hydraulic actuator 33 is mounted upon the bracket 25 and contains a piston 35 which can be actuated by hydraulic or pneumatic pressure fluid from one of two supply lines 37 and 38 controlled by valves 39 and 41 on the surface of the platform P. Thus, after the first row of pipe 29 has been racked, hydraulic fluid under pressure is supplied through the line 38 to move the piston 35 to the left and draw the device 23 to the left one pipe diameter for uncovering additional space for the next row of pipe.

Upon completion of the racking operation the pipes 29 are distributed in orderly rows within the rack R and their upper ends are staggered from row to row, as shown clearly in FIGS. 3 and 4 so that it is a relatively simple matter for the derrick man to attach his tongs to the top of each pipe as it is to be withdrawn from the rack and introduced into the well.

An alternative way for operating the novel pipe rack is to use the distributing device 23 as a pusher instead of only as a guide. For example, the device 23 is retracted to the left and as each length of pipe 29 is lowered onto the floor 15 the device 23 is actuated toward the right in FIG. 2 to push that pipe to its final position. Then the pusher is retracted until the next pipe is inserted and ready to be pushed into place.

From the foregoing description it is evident that I have provided a novel pipe rack construction which permits the derrick man to work at the rig floor level for safety and efliciency rather than at the top of the derrick as in conventional practice. Also, I have increased the safety and reduced the down time due to handling drill pipe in weather in which a floating vessel tends to roll excessively. Furthermore, I have reduced the stresses placed on the drilling mast by eliminating the need to stack pipe against the mast, and I have also stabilized floating drilling vessels by lowering their centers of gravity.

Obviously, many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

I claim:

1. A pipe rack for well drilling apparatus mounted on a floating platform and comprising an elongated hollow box having an upper end adapted for mounting on said platform and a lower end closed by a floor, said floor being an inclined plane having an upper edge at one side of said box and a lower edge at the opposite side of said box, a pipe distributing member located near the lower end of said box and reciprocatively movable transversely of said box, said distributing member having a planar top surface inclined at substantially a right angle to the direction of inclination of said floor, said top surface having a lower edge at about the same level as said upper edge of said floor.

2. A pipe rack in accordance with claim 1 including remotely controlled actuating means attached to the lower portion of said box for moving said pipe distributing member back and forth in a plane transverse to said box, and control mechanism located on said platform connected to said actuating means for controlling the movement of said pipe distributing member.

References Cited UNITED STATES PATENTS 1,018,729 2/1912 Sine 211-69 2,606,003 8/1952 McNeil] 175-7 2,662,797 12/1953 Moon 182l'l4 2,701,089 2/ 1955 Fischer 229-16 2,999,549 9/ 1961 Stratton l--5 FOREIGN PATENTS 228,811 2/ '1925 Great Britain.

ROY D. FRAZIER, Primary Examiner.

CLAUDE A. LE ROY, Examiner.

W. D. LOULAN, Assistant Examiner. 

1. A PIPE RACK FOR WELL DRILLING APPARATUS MOUNTED ON A FLOATING PLATFORM AND COMPRISING AN ELONGATED HOLLOW BOX HAVING AN UPPER END ADAPTED FOR MOUNTING ON SAID PLATFORM AND A LOWER END CLOSED BY A FLOOR, SAID FLOOR BEING AN INCLINED PLANE HAVING AN UPPER EDGE AT ONE SIDE OF SAID BOX AND A LOWER EDGE AT THE OPPOSITE SIDE OF SAID BOX, A PIPE DISTRIBUTING MEMBER LOCATED NEAR THE LOWER END OF SAID BOX AND RECIPROCATIVELY MOVABLE TRANSVERSELY OF SAID BOX, SAID DISTRIBUTING MEMBER HAVING A PLANAR TOP SURFACE INCLINED AT SUBSTANTIALLY A RIGHT ANGLE TO THE DIRECTION OF INCLINATION OF SAID FLOOR, SAID TOP SURFACE HAVING A LOWER EDGE AT ABOUT THE SAME LEVEL SAID SAID UPPER EDGE OF SAID FLOOR. 